As a conventional flow rate control valve applied to the flow rate control of the cooling water for the vehicle, for instance, a flow rate control valve disclosed in the following Patent Document 1 is known.
This flow rate control valve is used for distribution control of the cooling water to auxiliary devices such as a radiator and a heater. The flow rate control valve has a substantially cylindrical housing whose axial direction one end side is open as an introduction port and which has a plurality of exhaust ports that are open on a peripheral wall of the housing, and a valve body which is rotatably accommodated at an inner peripheral side of the housing and whose axial direction one end side is open toward the introduction port and which has a plurality of opening portions on a peripheral wall of the valve body. The flow rate control valve can distribute the cooling water introduced from the introduction port to each auxiliary device according to a rotation position of the valve body, i.e. according to an overlap state between each opening portion and each exhaust port, through an inner peripheral side passage of the valve body and the opening portion and the exhaust port which are in the overlap state.